Patents by Inventor Rakesh Roshan

Rakesh Roshan has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 9326348
    Abstract: An illumination system comprises at least two light sources (101,102,103) having different emission spectra to one another; a detection circuit (131,132,133) for sensing a light intensity using at least one of the light sources as a photosensor; and driving means (161,162,163) for driving the light source in dependence on the sensed spectral distribution of light. The emission spectrum of a light source with the smallest bandgap overlaps the emission spectrum of a light source with the second-smallest bandgap. The illumination system is possible to measure the intensity of light emitted by the light source with the smallest bandgap by putting the light source with the second-smallest bandgap in detection mode. The illumination system may also sense the spectral distribution of ambient light, to allow the output from the illumination system to be adjusted in dependence on the ambient light.
    Type: Grant
    Filed: March 23, 2008
    Date of Patent: April 26, 2016
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Rakesh Roshan, Benjamin James Hadwen, David James Montgomery, Jonathan Heffernan
  • Patent number: 7979766
    Abstract: An aspect of the present invention reduces the additional number of signal lines of a bus for control signals by using a set of signal lines to transfer data bits in some durations and to transfer control signals in some other durations. In one embodiment, the same signal lines are used to transfer data in a data transfer phase, and for bus arbitration in a bus arbitration phase. As a result, the total number of signal lines of a bus (bus width) is reduced. According to another aspect of the present invention, an arbitrator block allocates the bus to one of the requesting modules according to an assigned priority and least recently used (LRU) policy.
    Type: Grant
    Filed: September 8, 2004
    Date of Patent: July 12, 2011
    Assignee: Centre for Development of Telematics
    Inventors: Manish Sharma, Rakesh Roshan, Manjunath Bittanakurike Narasappa, Bhavani Shanker Arunachalam, Suresh Radhakrishna, William Clement, Joe Jaisingh
  • Publication number: 20100182294
    Abstract: An illumination system comprises at least two light sources (101,102,103) having different emission spectra to one another; a detection circuit (131,132,133) for sensing a light intensity using at least one of the light sources as a photosensor; and driving means (161,162,163) for driving the light source in dependence on the sensed spectral distribution of light. The emission spectrum of a light source with the smallest bandgap overlaps the emission spectrum of a light source with the second-smallest bandgap. The illumination system is possible to measure the intensity of light emitted by the light source with the smallest bandgap by putting the light source with the second-smallest bandgap in detection mode. The illumination system may also sense the spectral distribution of ambient light, to allow the output from the illumination system to be adjusted in dependence on the ambient light.
    Type: Application
    Filed: March 23, 2008
    Publication date: July 22, 2010
    Inventors: Rakesh Roshan, Benjamin James Hadwen, David James Montgomery, Jonathan Heffernan
  • Publication number: 20100115357
    Abstract: An aspect of the present invention reduces the additional number of signal lines of a bus (180) for control signals by using a set of signal lines to transfer data bits in some durations and to transfer control signals in some other durations. In one embodiment, the same signal lines are used to transfer data in a data transfer phase, and for bus arbitration (150) in a bus (180) arbitration phase. As a result, the total number of signal lines of a bus (180) (bus width) is reduced. According to another aspect of the present invention, an arbitrator (150) block allocates the bus (180) to one of the requesting modules according to an assigned priority and least recently used (LRU) policy.
    Type: Application
    Filed: September 8, 2004
    Publication date: May 6, 2010
    Applicant: Centre for Development of Telmatics
    Inventors: Manish Sharma, Rakesh Roshan, Manjunath Bittanakurike Narasappa, Bhavani Shanker Arunachlam, Suresh Radhakrishna, William Clement, Joe Jaisinch
  • Patent number: 7686493
    Abstract: A display comprises a light source and an image display panel disposed in an optical path from the light source. The light source comprises a primary light source for illuminating a re-emission material which comprises at least a first nanophosphor material for, when illuminated by light from the primary light source, re-emitting light in a first wavelength range different from the emission wavelength range of the primary light source. The image display panel comprises a first filter having a first narrow passband or a first narrow absorption band, the first narrow passband or first narrow absorption band being aligned or substantially aligned with the first wavelength range. The combination of a narrow wavelength range emitted by the first nanophosphor material and the narrow passband or narrow absorption band of the filter allows a display with high efficiency and a high NTSC ratio to be obtained.
    Type: Grant
    Filed: October 1, 2007
    Date of Patent: March 30, 2010
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Rakesh Roshan, Peter Neil Taylor, David James Montgomery
  • Patent number: 7605011
    Abstract: A semiconductor device comprises an active region (4), a cladding layer (5,7), and a saturable absorbing layer (6) disposed within the cladding layer. The saturable absorbing layer comprises at least one portion (11a) that is absorbing for light emitted by the active region and comprises at least portion (11b) that is not absorbing for light emitted by the active region. The fabrication method of the invention enables the non-absorbing portion(s) (11b) of the saturable absorbing layer (6) to produced after the device structure has been fabricated. This allows the degree of overlap between the non-absorbing portion(s) (11b) of the saturable absorbing layer (6) and the optical mode of the laser to be altered after the device has been grown.
    Type: Grant
    Filed: July 24, 2007
    Date of Patent: October 20, 2009
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Rakesh Roshan, Brendan Poole, Stewart Edward Hooper, Jonathan Heffernan
  • Publication number: 20080084706
    Abstract: A display comprises a light source and an image display panel disposed in an optical path from the light source. The light source comprises a primary light source for illuminating a re-emission material which comprises at least a first nanophosphor material for, when illuminated by light from the primary light source, re-emitting light in a first wavelength range different from the emission wavelength range of the primary light source. The image display panel comprises a first filter having a first narrow passband or a first narrow absorption band, the first narrow passband or first narrow absorption band being aligned or substantially aligned with the first wavelength range. The combination of a narrow wavelength range emitted by the first nanophosphor material and the narrow passband or narrow absorption band of the filter allows a display with high efficiency and a high NTSC ratio to be obtained.
    Type: Application
    Filed: October 1, 2007
    Publication date: April 10, 2008
    Inventors: Rakesh ROSHAN, Peter Neil TAYLOR, David James MONTGOMERY
  • Publication number: 20070263691
    Abstract: A semiconductor device comprises an active region (4), a cladding layer (5,7), and a saturable absorbing layer (6) disposed within the cladding layer. The saturable absorbing layer comprises at least one portion (11a) that is absorbing for light emitted by the active region and comprises at least portion (11b) that is not absorbing for light emitted by the active region. The fabrication method of the invention enables the non-absorbing portion(s) (11b) of the saturable absorbing layer (6) to produced after the device structure has been fabricated. This allows the degree of overlap between the non-absorbing portion(s) (11b) of the saturable absorbing layer (6) and the optical mode of the laser to be altered after the device has been grown.
    Type: Application
    Filed: July 24, 2007
    Publication date: November 15, 2007
    Inventors: Rakesh Roshan, Brendan Poole, Stewart Hooper, Jonathan Heffernan
  • Patent number: 7263115
    Abstract: A semiconductor device comprises an active region (4), a cladding layer (5,7), and a saturable absorbing layer (6) disposed within the cladding layer. The saturable absorbing layer comprises at least one portion (11a) that is absorbing for light emitted by the active region and comprises at least portion (11b) that is not absorbing for light emitted by the active region. The fabrication method of the invention enables the non-absorbing portion(s) (11b) of the saturable absorbing layer (6) to produced after the device structure has been fabricated. This allows the degree of overlap between the non-absorbing portion(s) (11b) of the saturable absorbing layer (6) and the optical mode of the laser to be altered after the device has been grown.
    Type: Grant
    Filed: April 1, 2004
    Date of Patent: August 28, 2007
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Rakesh Roshan, Brendan Poole, Stewart Edward Hooper, Jonathan Heffernan
  • Publication number: 20040233952
    Abstract: A semiconductor device comprises an active region (4), a cladding layer (5,7), and a saturable absorbing layer (6) disposed within the cladding layer. The saturable absorbing layer comprises at least one portion (11a) that is absorbing for light emitted by the active region and comprises at least portion (11b) that is not absorbing for light emitted by the active region.
    Type: Application
    Filed: April 1, 2004
    Publication date: November 25, 2004
    Inventors: Rakesh Roshan, Brendan Poole, Stewart Edward Hooper, Jonathan Heffernan
  • Patent number: D872170
    Type: Grant
    Filed: May 9, 2018
    Date of Patent: January 7, 2020
    Assignee: OXSIGHT LIMITED
    Inventors: Robert Evans, Steve Green, Rupert Wilkinson, Terry Gander, Stephen Hicks, Athar Ali, Rakesh Roshan, Daniel Crown